Morphometrics and compositional classes. The study of anthropomorphic sculptures from Teotihuacan (México). (original) (raw)
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Morphometric Analysis Applied to the Archaeological Pottery of the Valley of Guadalquivir
Ceramics are one of the most documented materials in the archaeological interventions. The documentation and the analysis of the pottery shapes allow the knowledge of the chronology and the functionality of the settlement where they have been found. The achievement of a typology of ceramic materials is made attending on different aspects (function, context, morphometry. . .). In this contribution a methodology of analysis of archaeological ceramic is showed. This methodoly is based on the technique of nonrigid deformable analysis applied to the drawing of the profile and is aimed at the construction of a ceramic typology.
Some Applications of Geometric Morphometrics to Archaeology
This work explores some aspects of the application of geometric morphometric techniques in archeology, with a focus on lithic artifacts. We show that Elliptic Fourier Analysis and landmark/semi-landmark based methods can easily generate quantitative useful information relative to outline variation in lithic artifacts. This information can be used latter as raw data into univariate, multivariate analysis to explore mayor trends of morphological variation as well as relations between metric and morphological variation.
We present here a newly developed software package named Artifact GeoMorph Toolbox 3-D (AGMT3-D). It is intended to provide archaeologists with a simple and easy-to-use tool for performing 3-D landmarks-based geometric morphometric shape analysis on 3-D digital models of archaeological artifacts. It requires no prior knowledge of programming or proficiency in statistics. AGMT3-D consists of a data-acquisition procedure for automatically positioning 3-D models in space and fitting them with grids of 3-D semi-landmarks. It also provides a number of analytical tools and procedures that allow the processing and statistical analysis of the data, including generalized Procrustes analysis, principal component analysis, a warp tool, automatic calculation of shape variabilities and statistical tests. It provides an output of quantitative, objective and reproducible results in numerical, textual and graphic formats. These can be used to answer archaeologically significant questions relating to morphologies and morphological variabilities in artifact assemblages. Following the presentation of the software and its functions, we apply it to a case study addressing the effects of different types of raw material on the morphologies and morphological variabilities present in an experimentally produced Acheulian handaxe assemblage. The results show that there are statistically significant differences between the mean shapes and shape variabilities of handaxes produced on flint and those produced on basalt. With AGMT3-D, users can analyze artifact assemblages and address questions that are deducible from the morphologies and morphological variabilities of material culture assemblages. These questions can relate to issues of, among others, relative chronology, cultural affinities, tool function and production technology. AGMT3-D is aimed at making 3-D landmarks-based geometric morphometric shape analysis more accessible to archaeologists, in the hope that this method will become a tool commonly used by archaeologists.
This work involves the creation of a taxonomy of three-dimensional posture and gesture combinations represented by ceramic human figures associated with shaft and chamber tombs in the western coastal states of Nayarit, Jalisco, Michoacán and Colima of Mexico. Gordon Hewes (1966) proposed that posture and gesture of actual human subjects communicates a tremendous amount of information that was not being gathered on a consistent basis (Hewes 1966:106). While Hewes presented his paper on "The Domain Posture" fifty years ago, his observation rings true today. The three-dimensional taxonomy should demonstrate that posture and gesture are correlated with sexual characteristics and are not random, but rather, an illustration of a purposeful series of postures and gestures that transmit cultural meaning within the ancient constructs of West Mexican culture. There is an opportunity for anthropologists to begin seeing and evaluating and documenting the non-verbal communications made through posture and gesture both in artefacts crafted as figures, as in the case of the shaft tomb figures, and in modern cultural anthropology.
Curvature-Based Method for Morphometric Analysis of Archaeological Shapes
This contribution will look at a particularly effective method of curvature-based analysis of two-dimensional outlines. See Kampel and Zambanini (Chapter 5, this volume), who introduce the general idea of curvature-based analysis. I apply this method to examine global and localized differences in the endocranial outline of a small sample of fossil hominins and modern humans. Other archaeological applications of this curvature-based method include the shape analysis and classification of artifacts with smooth outlines, such as groundstone and shell preciosities. For example, the curvature of points along two-dimensional outlines of artifacts could be used as a multivariate raw data set for a classification analysis based on shape, which I will present in a future paper. Please note that I should have mentioned in this chapter that Dr. Dwight Read (UCLA) directed me to the transformation of the elliptical Fourier function to a curvature function, which he had discussed in his 1997 book chapter, please see: Read, D.W. 1997. Growth and form revisited. pp. 45–73. In: P.E. Lestrel (ed.). Fourier Descriptors and their Applications in Biology. Cambridge University Press, New York, New York.
Curvature-Based Method for the Morphometric Analysis of Archaeological Shapes
This contribution will look at a particularly effective method of curvature-based analysis of two-dimensional outlines. See Kampel and Zambanini (Chapter 5, this volume), who introduce the general idea of curvature-based analysis. I apply this method to examine global and localized differences in the endocranial outline of a small sample of fossil hominins and modern humans. A previous morphometric study (Bookstein et al. 1999), which used procrustes analysis of semi-landmarks, compared the endocranial outlines of 21 fossil hominins and modern humans provided a surprising result. Specifically, that the shape of the mid-sagittal endocranial frontal bone profile of the fossil and modern humans was very similar. The fossil hominin sample used in the Bookstein et al. study consisted of three Homo heidelbergensis (Bodo, Kabwe, and Petralona), the Spanish Atapuerca SH5 cranium (possibly proto-Neanderthal), and a “classic” Homo neanderthalensis skull, Guattari I.
Although the potential of morphometrics for the study of archaeological artefacts is recognized, quantitative evaluation of the concordance between such methods and traditional typology and the potential of these techniques as supported methodologies in the archaeological analysis is a pending task. We present a new method to characterize and classify wheel-made pottery by its profile , using Mathematical Morphology. Each piece is represented as a vector, obtained by sampling the so called morphological curves (erosion, dilation, opening and closing), and Euclidean Distance is used as a similarity measure. The proposed technique has been studied using a sample of 1133 complete ceramic vessels from the Iberian archaeological sites from the upper valley of Guadalquivir River (Andalusia, Spain), showing that it is compatible with the existing corpus, established by experts.
The promise of geometric morphometrics
American Journal of Physical Anthropology, 2002
Nontraditional or geometric morphometric methods have found wide application in the biological sciences, especially in anthropology, a field with a strong history of measurement of biological form. Controversy has arisen over which method is the "best" for quantifying the morphological difference between forms and for making proper statistical statements about the detected differences. This paper explains that many of these arguments are superfluous to the real issues that need to be understood by those wishing to apply morphometric methods to biological data. Validity, the ability of a method to find the correct answer, is rarely discussed and often ignored. We explain why demonstration of validity is a necessary step in the evaluation of methods used in morphometrics.
Classical Sculpture Analysis via Shape Comparison
2013 International Conference on Culture and Computing, 2013
Modern 3D digital archiving technique provides a reliable assistance to archaeologists. In this paper, we explore a novel framework for digital classical sculpture comparison. Quantitative comparison is introduced, and shape difference is visualized as an indicator to infer unclear points about statue reproduction process in Roman period. Providing a new perspective for the culture relics study, our method plausibly verifies several important assumptions.
Journal of archaeological science: Reports, 2024
In Uruguay, Geometric morphometrics (GM) studies in archeology have been exclusively applied to “Fishtail” projectile points. The variability observed in this morphotype is attributed to the modifications due to diverse events such as resharpening or reworked during the history life. In this work, we aim to expand the recognition of the morphological variability of the archaeological lithic projectile point with stem from Uruguay, advance on the functional aspects of these projectiles, and discuss their link with the weapons systems that were used by the indigenous populations of the region. Through optical magnification and non-parametric statistical analysis, we characterize the allometric variation of n = 84 lithic projectile points. To gain independence from the ontogenetic changes, we selected 36 basic designs and analyzed their morphological variation GM. Based on their weight, we were allowed to assign them to the arrow, dart, and spear categories. The principal components analysis and partial least squares showed that shape changes are associated with the blade-stem relationship, which is proportionality 1:1 and 2:1 in negative values and > 2.5:1 and > 3:1 in the positive values. Arrows and darts share the 1:1 and 2:1 relationship morphospaces of this structure. Darts and spears share the one defined by the ratio > 2,5:1 and, finally, the morphospace defined by the ratio > 3:1 was exclusively integrated for spears. The standardization of proportionalities found in this contribution crosses morphological variability and allows us to discuss the versatility of designs and the complementarity between weapon systems.